Solenoid valve having a poppet stem and spring biased floating pole piece



I United States Patent 1 1 3,538,954

[72] Inventors Richard A. Fagerlie [56] Refer Cit d Union Lake; w M hUNITED STATES PATENTS James Buwshe" 3,420,492 1 1969 Ra 251 129x JamesA-Twnshil 2,692,354 10/1954 mi ler... 335/264X Oakland 2,910,089 10/1959Yarber 137/625.65 I211 APPl- 772,456 2,930,404 3/1960 Kowalski et al..251/129x [22] Filed Oct. 14,1968 v I Continuation-impart of Ser. N0.657,813, Primary W Klmkslek Aug. 2, 1967, abandoned, At orney- Donnelly.Mentag and Harnngton [45] Patented Nov. 10,1970 [73] Assignee MACValves, Inc.

Oak Park, Michigan acorporauon ofMlchlgan ABSTRACT: A solenoid-operatedreversing valve having a poppet stem normally blased to a first positionby a return 541 SOLENOID VALVE HAVING A POPPET STEM AND film"? i' i 'fprmg y a so eno1 p unger to effect a flu1d SPRING BIASED i i POLE PIECEseal at said second position, and which solenoid plunger is 21cmmsamawmg adapted to coact with a spring-biased floating solenoid pole[52] US. Cl ..l37/625.65, piece which compensates for variations betweenthe magnetic 251/129, 251/141; 335/259, 335/264 seal position of thesolenoid plunger and the fluid seal position [51} Int. Cl ..Fl6k 11/02,of the poppet stem so as to effect a substantially simultaneous F 1 6k31/02. H0 1 f 2/08 magnetic seal between the solenoid plunger and thepole piece [50] Field of Search 335/259, when the poppet stem effectsthe fluid seal between a poppet valve carried on the poppet stem and avalve seat.

Patented Nov, 10, 1970 3,538,954

Sheet 2 M2 gzfE.5

a 49}: m 7:! 44 L J- 82 E7 4&1 5/1 42, BL INVENTORS.

44d RICHARD A. FAGEPL/E BYJAMES [P.BOWSHEP 9 JA/v'IES AWEQFE ATTORNEYSSOLENOID VALVE HAVING A POPPET STEM AND SPRING BIASED FLOATING POLEPIECE SUMMARY OF THE INVENTION This application is acontinuation-in-part application of U.S. Pat. application Ser. No.657,813, filed Aug;.2,.l967 and now abandoned.

This invention relates generally to solenoid-operated reversing valves,and more particularly, to a novel and improved solenoid reversing valvehaving a poppet stem and a spring-biased floating pole piece which'isadapted to compensate for variations between the sealed or closedposition of the solenoid and the sealed or closed position'of the poppetvalve on a valve seat.

I-Ieretofore, poppet-type valve constructions have been employed toprovide small, alternating current, solenoidoperated reversing valveswith as large or maximum" amount of flow as possible, and with a minimumstroke of the solenoid plunger. However, a disadvantage of such priorart valves is that it is not possible to achieve asubstantiallysimultaneous solenoid seal and a fluid seal without the provision ofsome type of a flexible coupling between the solenoid and the poppetstem, such as a spring means, to allow the solenoid to seal magneticallyafter the valve elements have achieved the fluid seal and reduce theinrush current to a holding current level to prevent overheating of thesolenoid. The problem of providing an efficient magnetic sealsimultaneously with the effecting of the fluid seal is furthercomplicated by the tolerances of the various parts of the solenoid andvalve structures. Another disadvantage of the prior art valves of thistype is that they have valve seats and valve ports disposed in certainlocations on the solenoid plunger and valve structure, and are formed tocertnin sizes to provide the desired flow and pressurechurnclcl'itllltitl, but such valve seat und port locations and sizescause unbalanced conditions in said valves.

Accordingly, in view of the foregoing, it is an important object of theinvention to provide a solenoid-operated reversing valve which isconstructed and arranged to overcome the aforementioned disadvantages ofthe prior art solenoidoperated reversing valves.

It is another object of the invention to provide a novel and improvedsolenoid-operated reversing valve which is provided with means forobviating the necessity of a flexible coupling between the solenoid andthe poppet valve actuator, and which means includes a spring-biasedfloating pole piece that moves to close the solenoid magnetic circuitsubstantially simultaneous with the effecting of the valve closing bythe solenoid plunger.

It is still another object of the invention to provide a novel andimproved solenoid reversing valve which is provided with a balancedpoppet-type valve construction that includes a circular poppet or sealof compressible material, such as rubber, which is molded to asupporting poppet stem in such a manner that when the poppet stem isinserted in a poppet valve bore'of' substantially smaller diameter thanthe poppet, the poppet will be compressed sufficiently to allow passageof the poppet into a central fluid transfer chamber or cavity in thevalve and then expand and be reciprocated from one internal valve seatto another internal valve seat in said fluid transfer chamber to effeeta valving action sufflciently balanced to permit ease of operation andshort travel of the solenoid plunger and provide maximum flow with'aminimum of power.

It is still a further object of the invention to provide a novel andimproved solenoid-operated reversing valve which includes a valve body,said valve body being provided with at least one delivery port, and atleast on'e'exhaust port, said ports being connected to a valve stem borewhich is axially disposed in the valve body and which has at least onevalve seat formed therein, an axially shiftable poppet stem carrying apoppet seal mounted in the valve stem bore and movable from afirstposition' to a second position to seat said poppet seal onsaidvalve seat to control the flow of fluid between said ports, a returnspring mounted in the valve body and operative to normally bias thepoppet stemto said first position, a solenoid mountedon the valve bodyand having a solenoid plunger in contact with the poppet stem for movingthe poppet stem from said first position to the second position when thesole noid is energized, and a spring-biased floating pole piecedisposed'in a normal position spaced apart from the solenoid plunger,whereby when thesolenoid is energized, the solenoid plunger willmove-thepoppet'stem to said second position to effect the fluid seal with saidvalve seat and the mutual magnetic attraction between the solenoidplunger and the floating pole piece will move the pole piece into aclosed magnetic seal with the solenoid plunger substantiallysimultaneous with the effecting of the fluid seal.

It is still another object of the present invention to provide a noveland improved solenoid-operated reversing valve which is provided withamovable solenoid pole piece which functions to compensate for thedimensional limits and tolerances of the various machined parts employedin the construction of the solenoid and valve structures.

It is a further-object of the-invention to provide a novel and improvedsolenoid-operated reversing valve which is provided with a balanced,poppet-type valve construction that includes a pair of circular poppetsor seals made from a suitable compressible material and wherein the saidpoppets are operable in a valve chamber between two internal valve seatsformed around bores of a smaller diameter than the diameter of saidpoppets to insure effective sealing between the poppets and the. valveseats regardless of any change of diameter of the poppets due to wear orother reasons; and which poppets are molded to a supporting poppet stemand spaced apart by a circular metal flange having a diameter largerthan the valve seat bores to prevent the poppet stem from beingaccidentally removed from the valve chamber.-

It is still a further object of the invention to provide a novel andimproved solenoid-operated reversing valve having a valve stemvbore inwhich one valve seat is integrally formed, and a separately formedsleeve mounted in said bore and having a second valve seat formedthereon and disposed in a position spaced apart from said first valveseat, and axially shifta- 'ble poppet stern carrying a pair of poppetseals and movable between a first position and a second position toalternately seat said poppet seals on said valve seats to control theflow of fluid through the valve stem bore and between the usual inlet,delivery and exhaust ports, a return spring provided to normally biasthe poppet stem to said first position, a solenoid having a plunger incontact with the poppet stem for moving the poppet stem from said firstposition to the second position when the solenoid is energized, and aspring means for normally maintaining the solenoid plunger in contactwith the valve stem, and said valve being adapted to receive varioustypes of end cover fittings, as for example, a conduit-type end coverfitting, a grommet-type end cover fitting, and an explosion-proof-typeend cover fitting.

Other objects, features and advantages of this invention will beapparent from the following detailed description, appended claims, andthe accompanying drawings.

In the drawings:

FIG. 1 is a side elevational view of a solenoid-operated reversing valve.made in accordance with the principles of the present invention,

FIG. 2 is a top plan view of the structure illustrated in FIG. 1, takenalong the line 2-2 thereof, and looking in the direction of the arrows;

FIG. 3 is an elevational section view of the structure illustrated inFIG. 2,-taken along the line 3-3 thereof, and looking in the directionof the arrows;

FIG. 4 is a partial, enlarged, elevational section view of the floatingpole piece, poppet stem, and valve seat structures shown in FIG. 3;

FIG. 5 is an elevational section view, similar to that of FIG. 3, of asecond illustrative embodiment of the invention;

FIG. 6 is a fragmentary, elevational section view of the upper end ofthe second embodiment of FIG. 5, and showing said second embodimentprovided with another type of housing end cover designated as agrommet-type end cover;

FIG. 7 is a fragmentary, elevational section'view of the upper end ofthe first embodiment of FIG. 3, and showing said first embodimentprovided with another type of housing end cover designated as anexplosion-proof-type end cover; and

FIG. 8 is a fragmentary, elevational section view of the upper end ofthe second embodiment of FIG. 5, and showing said second embodimentprovided with still another type of housing end cover designated as amodified grommet-type end cover.

Referring now to the first illustrative embodiment shown in FIGS. Ithrough 4 of the drawings, and in particular to FIG. 3, the numeral 10generally designates a cylindrically shape valve body having a poppetstem that is generally indicated by the numeral 11 and which is movablymounted inv an axially disposed valve stem bore that is generallyindicated by thenumeral 12. A solenoid, generally indicated by thenumeral 13, is

i operatively mounted on the upper end of the valve body 10,

and it is adapted to shift the poppet stem 11 from a first operativeposition to a second operative position, as more fully described indetail hereinafter.

valve seats .18 and 22 when the poppet stem 11 is shifted Theillustrated valve formed by the valve body 10, the poppet stem 11 andsolenoid I3 is a solenoid-operated, three-way reversing valve. However,it will be understood that the invention is applicable to other types ofsolenoid-operated reversing valves, as for example, a two-way reversingvalve or a fourway reversing valve. The solenoid construction ofthepresent invention is adaptable to any application where compensationis required for tolerances between a first position and a secondposition of a valve stem or other member moved by the solenoid.

As shown in FIG. 3, the illustrated three-way reversing valve includesan inlet or suppiy port l4 that communicates through supply port 14 andthe cylinder port 21 are disposed on the same transverse plane. Thecylinder port or delivery port 21 is adapted to function as a port fordelivery and exhaustion of fluid under pressure to and from a fluidcylinder or other device to be supplied with fluid under pressure.

As shown in FIG. 3, the annular fluid transfer chamber 19 is connectedthrough a second valve seat or orifice 22 and the valve stem boreportion 23 to an annular exhaust chamber 24 that is formed in the wallof the valve stem bore 12. The ex-- haust chamber 24 communicatesthrough the radial fluid passage 25 with'an exhaust port 26 (FIG. 2). Itwill be understood that the inlet port 14 would be connected to asuitable source of fluid under pressure, as for example, a source ofpressurized air. The illustrated valve is constructed as a normallyclosed valve, but it may be changed to a normally open valve byswitching the flow through the inlet and exhaust ports 14 and 26,respectively. That is, the exhaust port 26 may be used as a pressurizedfluid inlet port, and the inlet port 14 may be used as an exhaust port.

As shown in FIGS. 3 and 4, the poppet stem 11 is substantiallycylindrical in overallconfiguration and is provided with a first'O-ringseal 27 which engages the lower end portion 28 with a second O-rin'gseal 29 which is spaced apart upwardly between its two operativepositions; As shown in FIG. 3, the return spring 34 normally biases thepoppet stem I1 upwardly to the solid line position which is the first ordeenergized position so as to normally close the passages between theinlet port 14 and the cylinder port 21 and communicate the exhaustchamber 24 with the cylinder'port 21. The broken line position 36 (FIGS.3 and 4) of the poppet stem 11 and its operating shaft 37 is the secondoractuated position to which the poppet stem 11 is shifted by thesolenoid 13 when it is energized, as more fully described hereinafter,so as to open the passages between the inlet port 14 and thedeliveryport 21 and close the passages between the cylinder port 21 andthe exhaust port 26.

. As best seen in FIG. 4, the outer diameter 38 of the poppet valve seal35 is larger than the diameter of the poppet valve stem bore 12. Thepoppet valve seal 35 is circular in cross section and ismade from acompressible material, such as rubber, which is molded to the supportingpoppet stem 11 in such a manner so that when the poppet stem 11 isinserted into the valve bore 12 the valve seal 35 will compresssufficiently to allow it to be passed into the central transfer chamber19 where it will then expand to its normal or free state. The poppetvalve seal 35 is cylindrical in overall configuration and the upper andlower ends thereof are slightly chamferedas indicated by the numerals 39and 40, respectively. The valve seats 18 and 22 are spaced apart axiallyand are disposed at the upper and lower ends of the transfer chamber 19,and the surfaces of thesevalve seats are slightly conical in shape so asto provide diverging surfaces facing the chamber 19. As shown in FIG. 4,the upper end surface of the valve seal 35 is seated against the valveseat 18 to effect a poppet valve action and a similar poppet valveaction is effected when the poppet stem 11 is moved downwardly to thedotted line position 36 so as to seat the lower chamfered seal periphery40 on the lower valve seat 22.

As shown in FIG. 4 the valve of the present invention is a substantiallybalanced valve since the sealing diameters are all substantially equal.That is, the diameter of the valve stem bore portion 30 is substantiallyequal to the sealing diameter effected by the valve seal 35 against thevalve seat 18, and the diameter of thevalve stem bore portion 28 is alsoequal to the diameter of thevalve stem bore portion 30 and the effectiveI sealing diameters formed when the valve seal 35 engages the valveseats 18 and 22.

The poppet valve seal 35 has only to be moved a very short distance inorder to effect a valving action in conjunction with the valve seats 18and 22. For example, in one embodiment the stroke of the valve stem 11was about .025 of an inch. The valve structure of the present inventionprovides a valve which may be provided with relatively large valve seatsor orifices 18 and 22 to provide a'relatively large flow of pressurizedfluid over a much broader pressure range 'than was heretofore possiblewith the prior art valves. The aforementioned illustrative embodimentwith the..025 of an inch stroke is adapted to operate over a pressurerange of from vacuum to I50 p.s.i. The valve of the present invention issubstantially a balanced valve with a slight pressure differential beingdeveloped at the point of contact between the poppet valve seal 35 andthe from the lower O-ring seal 27 and which operatively engages theupper valve stem bore portion 30;"ltwill' be seen that the diameters ofthe valve stem bore portions'28 and 30 are the same, and the O-ringseals 27 and 29 are equalin size.

As shown in FIGS 3 and'4, the lower end of the valve stem bore I2 isenclosed by a thin disc 31 whichfunctions as a spring seat. The disc 31is retained in place by a releasable retainer ring 32. The poppet stem11 is provided with an axial,

valve seat 22 when the poppet stem 11 is shifted to the broken lineposition 36. This slight pressure differential assists the sealingaction and it is caused by the valve seal 35 flattening out slightlywhen it seats on the valve seat 22 and reducing the area at the lowerend of the valve seal 35.

As shown in FIG. 3, the solenoid 13 includes a coil bobbin or supportmember 41 which is cylindrically shaped and mounted by a slip fit in thecylindrical solenoid housing or cover .42. The solenoid cover 42' isopen at the lower end thereof and it is telescopically mounted overthevalve body 10. The cover 42 is secured to the valyebody 10. by anysuitable means, as by the screw 43 (FIG. 2). The solenoid cover 42 maybe made from any suitable magnetic material. The upper end of thesolenoid cover 42 is enclosed by a nonmagnetic end plate 44 which isadapted to be secured in place by any suitable method as by staking orby brazing. A flux plate 45, made the valve seat 22. The fluid passagesbetween the cylinder port I 21 and the exhaust port" 26 are blocked. andthepassages between the cylinder port 21 and the-exhaust port 26 arefrom a suitable magnetic material, is mounted in the upper end-of thesolenoid cover 42 between the end plate 44 and the coil bobbin 41. Thecoil'bobbin 41 has an extension or protru sion 46 that extends throughan aperture 47 formed in the end plate 44 and which functions as agrommet for the-solenoid coil lead wires 48. v

I The-coil bobbin 41 may be made from any suitable material,

as for example. a molded plastic impregnated with fiber glass.

The coil bobbin 4I carries a solenoid coil assembly 49 which surrounds asolenoid plunger or armature 50. The solenoid plunger 50 is slidablymounted in the bobbin bore 51 and the flux plate bore 52, andthcrc is aclearance between the end plate 44 and the plunger 50 when the plunger50 is in the solid line position of FIG. 3.with the seal 35 on'valvcseat 18. The solenoid coil'assembly 4) is adapted to be connected to asuitable source of alternating current by the aforementioned lead wiresor electrical cables 48.

As shown in FIG. 3, the solenoid I3 includes a floating or blocked; andthe passages between the cylinder port 21 and the inlet port 14 areopened. Fluid under pressure then passes from the inlet chamber 16 andthrough the valve seat 18. the transfer chamber 19. the passage 20, andout through the cylinder port 2I to the device being provided with fluidunder pressure.

The aforcdescribed action effects the fluid seal between the valve seal35 and the valve seat 22. The magnetic seal between the lower end of thesolenoid plunger 50-und the upper end of the floating pole piccc shaft55 is effected in a substantially simultaneous action with the fluidscaling action. Assuming that the initial airgap between the lower end62 of the sole noid plunger 50 and the upper end 63 of the flouting polepiece shntt'55 is equal to about .040 inches, after the solenoid plunger50 has moved downwardly for a travel of about .025

I inches so as to move the valve seal 35 into seating engagement axiallymovable, spring-biased pole piece which is generally I indicated by thenumeral 53. The floatingpole piece 53 is inverted T-shaped in. crosssection, and it includes an annular flange portion 54 which is disposedbetween'the' lower end of the coil bobbin 4l and the top end of thevalve body 10. The

- floating pole piece 53 further includes the cylindrical shaft 55 whichis integral with the plate portion 54 and which extends axially upwardinto the bobbin bore 51. The floating. pole piece shaft 55 is providedwith'an axial bore 56 through which passes the operating shaft 37 of thopoppet stem 11. The floating pole piece shaft 55 carries a circularshading coil 57 on the upper end thereof, in a position facing thelowerjend of the solenoid plunger 50. The shading coil 57 provides anover- Iappingmagnetic flux seal to insure holding of the solenoidplunger 50 against the floating pole piece 53 when the'solenoid c'oilassembly 49 isenergizcd with alternating current.

.The floating pole piece 53 is normally biased downwardly by the coilspring 59 so that; the annular shoulder 58 on the lower end of the polepiece seats on the upper end of the valve body I0. The coil spring 59 isseated around the floating pole piece shaft 55 and the lower end thereofseats on the upper face 60 of the annular flange 54, and the upperend-of the spring 59 seatsagainst the lower surface 61 of the coilbobbin 41. The space between the lower, end 62 of the solenoid plunger50 and the upper end 63 of the floating" pole piece shaft 55 comprisesthe initial air gap between these members when the solenoid coilassembly 49 is deenergized'ln one em;

bodiment the spring 59 was formed to provide a working force of 2pounds'while the poppet stem return spring 34 was formed to provide aworking force of I pound. The numeral 64 designates a-dust'shield whichencloses the-plunger access hole 65 formed in the end plate 44. 1 Inoperation, the initial normally closed positions of the poppet stem 11and the solenoid plunger 50 are shown by the solid line positionsofthe'se parts in FIGS. 3 and 4. Fluid under pressure enters the inletport 14 and passes through the passage 15 into thc'inlet chamber 16. Thevalve seal 35 is seated on the valve seat 18 under the biasing action ofspring 34 and the fluid isblocked in the inlet chamber 16. The fluid inthe device being controlled by the valve is exhaust'ed through thecylinder port 21, the passage 20, the transfer chamber 19,'the valvestem bore portion 23, the exhaustchamber 24, the passage (FIG. 2), andthe exhaust port 26.

cylinder port 21, the solenoid coil assembly 49 is energized and theplunger 50 is pulled downwardly so as to overcome the force of spring 34and move the poppet stem shaft 37 and with the valve seat 22,- therewill be about u .OIS inch gapbetween said two surfaces. During saidtravel of .025 inches, the floating pole piece spring 59 overcomes themutual attrae' tion-of the solenoid plunger 50 and the floating polepiece 53 and maintains the pole piece in the solid line position shownin FIGS. 3 and 4. However, after thesolenoid plunger 50 has movedthrough said .025 inches'travel and reached a positive stop with thevalve seal seated onthe valve seat 22, the attraction between thesolenoid plunger 1 nd the floating pole v piece shaft SSincrcases sothat at this point the mutual attracthe solenoid and the scaled orclosed position of the poppet non-between the solenoid plunger 50 andthe floating pole piece 53 is strong enough to overcome the holding-downforce of the spring 59, and the floating pole piece 53 snaps upwardly tomeet the solenoid plunger 50 along the broken line 66 and effecta-closed m'agnetic circuit between the solenoid plunger 50 and thefloating pole piece 53 and reduce the inrush current to aholdingcurrent.The floating pole piece 53 compensates for machinetolerances between the various parts of the solenoid and valvestructures.

The structure of the valve of the present invention compensates forvariations between the sealed or closed position of seal 35 on the valveseat 22. The floating pole piece 5311b: viates the necessity for anyflexible coupling between thepoppet stem and the solenoid plunger 50v asis required in the prior art alternating current, solenoid-operatedreversing valves. The circularpoppet seal 35 ltas an effective sealingdiameter equal to the outer diameter of the seals 27- and 29 when theseal 35 engages the valve seats 18 and 22 and provides a poppet valvestructure which is adapted to be reciprocated from one operativeposition to another with a balanced valvingaction with ease ofoperation, and with a minimum stroke of the When it is desired to admitfluid to said device through the FIG. 5 illustrates a second embodimentof the invention;

solenoid plunger 50 and poppet stem 11.

The parts of the second embodiment of FIG. 5 which are thesame as theparts of the first embodiment ofFlGS. I through 4 have been marked withcorresponding'reference nutneruls'followed by the small letter "a. Thesecond embodiment of FIG. 5 functions in the same'manner as the firstembodiment of FIGS. 1 through 4.

One of the differences between the second embodiment of FIG. 5 andthe'tirst embodiment of FIGS. 1 through 4 is that the poppet seal meanshas been made in two parts which are indicated'by the numerals 35a.Thetwo poppet seal'members 35a are molded on the poppet stem 11a onopposite sides of a metal'flange 67. The metal flange 67 is formed withan outer diameter larger thun'the diameter of the bores 17a and 23athrough the valve seats 18a and 220, respectively. The metal flange 67functions to prevent the poppet stem I-Ia from being pulled out of thevalve stem bore 17a. The poppet seal mem-' bers 35a are formed with anouter diameter larger than they valve stem bores l7a and 23a so thatthey engage the valve As shown in FIG. 5, the return spring 3411 is notsupported I by any disc, as the disc 31 shown in the first embodiment ofFIG. 3. The return spring 34a seats against the innerend wall of thevalve stem bore I2a. A vent bore 68 is'formed in the valve body 10a andcommunicates with the valve stem bore portion 28a.

As shown in FIG. 5, one of the valve seats, namel'y, 22a, is formed as apart of the valve body 10a. The other valve seat 18a is formed on avalve seat carrier or sleeve 69 which is slidably mounted in theenlarged outer end 72 of the valve stem bore 120. The valve seatcarrier'69 is provided with a pair of annular seal members 70 forsealing engagement with the enlarged valve stem bore portion 72. Thevalve seat carrier 69 is provided with a llange'73 against which ismounted the reception of the reduced outer end of the boss 76, to permitthe end cap 85 to be seated'on the shoulder 84 on the boss 76.

A lock nut 87 is threadably mounted on the reduced outer end of the boss76 to retain the end cap 85 in place. lntegrally l'ormed'ion one side ofthe cap 85 is a conduit fitting 88. The

conduit fitting 88 communicates through the opening 89 with i theinterioriof the end cap 85 to permit the solenoid lead wires 48a to beconnected to a suitable source of electric power.

The conduit fitting 88 also functions as a means for mounting the valvein an operative position.

An advantage of the structure of the second embodiment of FIG. 5 is thatit may be economically manufactured, because the valvestem bore 12a,with its various stepped portions, and the valve seat 22a may beeconomically and easily machined. The valve structure of FIG. 5 isadvantageous in that it may be quickly and easily disassembled forrepair purposes.

FIG. 6 is a fragmentary, clevational, section view of the upper end ofthe secondemhodiment of FIG. 5, showing the valve structure of FIG. 5provided with another type of housing end cover designated as agrommet-type end cover. The

9 parts ofthe solenoid housing and valve structureof FIG;6

retainer ring 74 for retaining the' valve seat carrier 69 in the valveseat bore portion The valve stem bore portion 17a communicates with theinlet chamber 16a by means ofa plurality oftransvcrse bores 71. 1

in the structure of the second embodiment of FIG 5, the

poppet valve stem operating shaft 37ais separately formed from thepoppet stem Ila and functions as aconnecting pusher rod between thepoppet stem Ila andthe solenoid plunger'SOa. The solenoid cover 420 isthreadably mounted on the valve body 10a as indicated by the referencenumeral 75.

A further difference between the second embodiment of FIG. 5 and thefirst embodiment of FIGS. I through 4 is that the floating pole pieceannular flange 54a is reduced in thicknessand in outer diameter ascompared to the annular flange 54. The coil spring 59a has its lower endseated on the upper face 60a of the reduced size annular flange 54a. Theupper end of the spring 590 seats against the lower face 92 ofa retainerring 93. The retainer ring'93 may be made from any suitable magneticmaterial and it is threadably mounted on the inside of the solenoidcover 42. The upper face of the retainer ring 93 abuts the lower face61a of the coil bobbin 41a. The

retainer ring 93 is seated around a cylindrical, axial extension 94 onthe lower end of the coil bobbin 4la. The retainer ring 93 retains thecoil bobbin 4Ia in position in the'housing 42a.

As shown in FIG. 5, the upper end of the solenoid housing 42a isenclosed by an end plate 444 which is made from a suitable magneticmaterial. The end plate 44a is adapted to be which are similar to thestructure of FIG. 5 have been marked with the samercl'crence numeralsfollowed by the small letter 17". In the embodiment or FIG. 6, the endplate boss 76b is not provided with any threaded end portion or otherstructure for mounting the conduit end cap 85. The valve structure ofthe embodiment of FIG. 6 functions in the same manner as the valvestructure of the previously described embodiments. I

FIG. 7 is a fragmentary, elevations], section view' of the upper end ofthe first embodiment of FIG. 3, showing said first embodiment providedwith another type of housing end cover designated as an explosion-prooftype end cover. The parts of secured in place by any suitable method, asby staking-or by brazing. The end 'plate 44a is provided with an axiallyextended boss or projection 76 in which is formed a bore 77 for thereception of the upper end of the solenoid plunger 50a, 7

The bore 77 communicates with a smaller diameter bore 79 in which isslidably mounted a manual operator or'button 1 generally indicated bythe numeral 80. The button 80 is made from a suitable nonmagneticmaterial and is provided on the inner end thercofwith an external flange'81 that has a tapered outer surface which seats on and mates with atapered I shoulder surface 78 between the bores 77 and 79. A dead endbore 82 is formed 'on the inner end of the button 80 and provides arecess for a resilient positioning means or spring 83.

The inner end of the spring 83 engages the outer end of the position thevalve may be disposed in.

The second embodiment of FIG. 5 is-provided with a conthe valvestructure illustrated in FIG. 7 which are the same as the valvestructure of FIG. 3 have been marked with the cor-- responding referencenumerals followed by the small letter C. In the embodiment of FIG. 7 thesolenoid cover 42: is

provided with an axially extended, internally threaded upper end 90 inwhich is threadably mountcdthc threaded conduit fitting 91. The'threadedconduit fitting 91 forms a mounting means for the valve of FIG. 7, aswell as a conduit for the solenoid lead wires 48C. The fitting 91 abutsthe end plate 440 which is nonmagnetic and retains the upper pole piece45c in position. e

FIG. 8 is 'a fragmentary,.elevational, section view of the upper end ofthe second embodiment of FIG. 5 showing said second embodiment providedwith still another type of housing end cover 44d designated as amodified grommet-type end cover. The parts of the structure of FIG. 8which are the same as the structure parts of FIG. 5 have been markedwith the same reference numerals followed by the small letter d. Theonly difference between the grommet-type end cover of FIG.

'6 and the structure of FIG. -8 is that-the solenoid plunger biasing'spring 83d in the embodiment of FIG. 8 is seated in a spring recess 82dwhich is formed in the outer end of the solenoid plunger 50d, instead ofin the manual operatororbutton While it will be apparent that thepreferred embodiments of the invention herein disclosed urewellcalculated to fulfill-the objects above stated, itwill be appreciatedthat the invention is susceptible to modification, variation and change.

duit-typc end .cover or housing which has an end cap portion a 85slidably mounted over-the solenoid end plate'44a. The end We claim: y I.A solenoid-operated reversing valve comprising:

a. a valve body having a valve stem bore with a valve seat,

and having at least one delivery port, andat least one ex-. haust port,and said ports communicating with said valve stem bore and valve seat; 7

b. a poppet stem, carrying a poppet seal means, movably mounted in saidvalve stem bore and shiftable between a first position to a secondposition to seat said poppet seal means on said valve seat to form afluid seal tocontrol the flow offluid between said ports; l .c. biasingmeans mounted in the valve body and engaged with said poppet stem tonormally bias the poppet stem to said first position,

d. a solenoid mounted on the valve body and having a solenoid plunger incontact with the poppet stem and normally moved by said poppet stem to aposition adjacent one end of the solenoid and for moving the poppet stemfrom said first position to the second position in opposition to saidbiasing means when the solenoid is energized; and

e. a floating pole piece disposed in a position adjacent the other endof the solenoid and including means for normally biasing the floatingpole piece to a position spaced apart from the solenoid plunger, wherebywhen the solenoid is energized the solenoid plunger will move the poppet stem to said second position to eflect a fluid seal with said valveseat, and the mutual magnetic attraction between the solenoid plungerand the floating pole piece will move the pole piece into a closedmagnetic seal with the solenoid plunger substantially simultaneous withthe effecting of said fluid seal.

2. A solenoid-operated reversing valve as defined in claim 1, whereinsaid means for biasing saidfloating pole piece apart from the solenoidplunger comprises a spring means.

3. A solenoid-operated reversing valve as defined in claim 1, whereinsaid biasing means for normally biasing the poppet stem to said firstposition comprises a return spring.

4. A solenoid-operated reversing valve as defined in claim 3, whereinsaid solenoid plunger isnormally biased by said poppet stem into adeenergized position.

5. A solenoid-operated reversing valve as defined in claim 3, I

wherein said solenoid plunger is normally biased by said poppet steminto a deenergized position against a resilient positioning means.

6. A solenoid-operated reversing valve as defined in claim 5, whereinsaid resilient positioning means comprises a spring means mounted inamanual solenoid operator member.

7. A solenoid-operated reversing valve as defined in claim 1, wherein:

a. said valve stem bore has a longitudinally extended fluid transferchamber formed around the periphery thereof,

with said first-named valve seat being disposed at one end of saidtransfer chamber, and with a second valve seat being disposed at theother end of said transfer chamber and an inlet port communicating withsaid second valve seat; and Y b. said poppet seal means being made to adiameter slightly larger than the diameter of the bore through valveseats and being made from a compressible material.

8. A solenoid-operated reversing valve as defined in claim 7,

wherein:

a. said valve seats are integrally formed on said valve body at theopposite ends of said fluid transfer chamber; and

b. said poppet seal means comprises a unitary seal member,

with one end of said seal member being adapted to engage said secondvalve seat when the poppet seal member is in said first position, andthe other end of said seal member being adapted to engage saidfirst-named valve seat when the poppet seal member is in said secondposition, and whereby the poppet seal member may be compressed andinserted into said fluid transfer chamber, and after the insertion ofthe poppet seal member into said chamber, the poppet seal member willexpand and be movable between said first and second positions.

9. A solenoid-operated reversing valve as defined in claim 7, v

wherein:

a. one of said valve seats is integrally formed on said valve body atone end of said fluid transfer chamber, and the other of said valveseats is formed on a tubular valve seat carrier member mounted in thevalve stem bore and in a position spaced apart from said one valve seat;and

b. said poppet seal means comprises a pair of poppet seal A l-.. membersmounted on said valve stem and being spaced apart by a flange. 10. Asolenoid-operated reversing valve as defined in claim 9, wherein saidflange has an outer diameter larger than the bore throu h the valveseats.

11. A so enoid-operated reversing valve as defined in claim 7, wherein:

a. said poppet stem is provided with an annular sealing means on eachside of said poppet seal means in positions spaced apart longitudinallyfrom the poppet seal means; and

b. said annular sealing means are each formed to an effective sealingdiameter equal to the effective sealing diameter of the poppet sealmeans to provide a balanced poppet valve construction.

12. A solenoid having a solenoid plunger contacting an extension on theoperating member of an apparatus for pushing said operating member froma first position to a second position, comprising:

a. a housing;

b. a solenoid coil mounted in said housing and having a solenoid plungerbore formed therethrough and slidably receiving said operating memberextension;

c. a solenoid plunger movably mounted in the solenoid coil bore andnormally biased by said operating member extension to a first positionadjacent one end of the coil; and

d. a floating pole piece disposed adjacent the other end of the coil andnormally biased to a position spaced apart from the solenoid plunger,whereby when the solenoid coil is energized the solenoid plunger will bepulled inwardly in the solenoid bore to its energized position in saidbore, and the floating pole piece will be pulled toward the solenoidplunger and into magnetic sealing contact therewith, while saidoperating member is moved from a first position to a second position.

13. A solenoid as defined in claim 12, wherein'said floating pole piececomprises:

a. an inverted T-shaped in cross section member disposed transversely tothe axis of movement of the solenoid plunger; and

b. means for normally biasing the T-shaped in cross section member tosaid position spaced apart from the solenoid plunger.

14. A solenoid as defined in-clai'm 13, wherein said means for normallybiasing the T-shaped in cross section member to i said position spacedapart from the solenoid plunger comprises a spring means.

15. A solenoid as defined in claim 14, wherein:

a. said inverted T-shaped in cross section member includes a shaftextended into said solenoid coil bore, and a flange on said shaft; and

b. said spring means is disposed about said shaft said solenoid coil andsaid flange.

16. A solenoid as defined in claim 12, including a flux plate disposedon said one end of the coil opposite to the end of the coil at which thefloating pole piece is disposed.

17. A solenoid as defined in claim 12, including a shading coil disposedon said floating pole piece, on the end thereof adjacent said coil.

18. The structure as defined in claim 12, wherein:

a. said apparatus comprises a fluid flow control valve; and

b. said operating member comprises an axially movable poppet stem.

19. A solenoid as defined in claim 12, wherein said housing is providedwith a conduit type end structure.

20. A solenoid as defined in claim 12, wherein said housing is providedwith a grommet-type end structure.

21. A solenoid as defined in claim 12, wherein said housing is providedwith an explosion-proof-type end structure.

between mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent954 Dated November 10, 1970 Richard A. Fagerlie, James R. Bowsher andJames A, Nei

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

F- Column 2, line 40, after "seat", "and" should be --an-.

Column 3, line 14, after "cylindrically", "shape" should be -shaped-Column 6, line 7 following "and", cancel "the exhaust port 26 are" .Co6, line 8, cancel ''blocked, and the passages between the cylinder portand".

SIGNED F'HLED FEB 231971 (SEAL) Attest:

Edward m. Fletch 1* mm E. SGHUYLER, JTB Officer Missions]? of Patents

